Grass Valley
- County:
- Nevada County
- County Seat:
- No
- Area (mi²):
- 5.996
- State:
- California
Grass Valley is a city located in Nevada County, California. Grass Valley has a 2026 population of 14,085. Grass Valley is currently growing at a rate of 0.01% annually and its population has increased by 0.04% since the most recent census, which recorded a population of 14,079 in 2020.